The Human Eye

The eye acts like a camera. Which structure or structures bend(s) the light coming into the eye so that clear, camera-like vision can be achieved?

cornea only

retina only

cornea, lens, and retina

cornea and lens

lens only

As a generalization, which of the following can we correctly say about photoreceptors?

Rod cells and cone cells are equally responsible for dim light vision, but color vision is the responsibility of specialty color cells.

Scientists have not yet determined whether rods or cones are responsible for dim light vision, although it is known that cones are responsible for color vision.

Rods detect color and cones detect dim light.

Rod cells are responsible for color vision. All retinal cells are responsible for dim vision.

Rods detect dim light and cones detect color.

The place on the eye where we find the greatest visual acuity, and thus the place we "use" when we need to focus on details, is ________.

fovea

cornea

retina

optic nerve

lens

Which of the following statements about color vision is NOT true?

The brain combines signals from the different types of cone cells to differentiate the colors of the visible spectrum.

There are three types of cone cells, corresponding to the three primary colors of light: red, green, and blue.

Activation of opsin by retinal triggers a cascade of events that sends signals to the brain.

Cone cells use different retinal molecules to absorb different wavelengths of light.

Which of the following statements is NOT true?

The optic nerve carries the optic messages to the brain.

The different opsin molecules determine which wavelength of light is best absorbed by that molecule.

The photoreceptors are on the innermost layer (the layer closest to the center) of the retina.

Cones are responsible for the reception of bright light.

Each opsin molecule is associated with a retinal molecule.

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